Recombinant Enzymes for Scar Treatment: Mechanism, Evidence and Clinical Use
Introduction: Why Recombinant Enzymes Are Changing Scar Treatment
Injectable recombinant enzymes are emerging as a minimally invasive option for managing hypertrophic scars, keloids, and post-surgical scarring. Clinical use of these formulations, notably pb-ee serum products developed by Proteos Biotech in Spain, started in Europe around 2012–2014 and has expanded globally over the last decade. For patients and practitioners tired of the limitations of older approaches, this biochemical strategy represents a genuine shift in how scar tissue can be addressed at the molecular level.
Recombinant enzymes are bio-engineered proteins used to manage scars by selectively degrading the dense, disorganized extracellular matrix that makes pathological scars raised, stiff, and symptomatic. Unlike conventional treatments such as corticosteroid injections, surgical revision, or laser therapies, recombinant enzymes provide a biochemical approach rather than mechanical methods for scar treatment. The key clinically used enzymes include recombinant collagenase, recombinant hyaluronidase (or lyase), and recombinant lipase. When combined, these enzymes can remodel dense scar tissue and surrounding fat cells while preserving healthy skin.
This article covers the mechanisms of action behind these enzymes, their clinical indications, injection protocols, safety data, and how pb-ee serum technology fits into the broader landscape of scar management. Whether you are a clinician evaluating new treatment modalities or a patient exploring options beyond silicone sheets and steroid injections, the information ahead is designed to be practical and evidence-based.
What Are Recombinant Enzymes? (With Focus on Dermatology and Aesthetics)
To understand why recombinant enzymes matter in scar treatment, it helps to start with what enzymes actually do in the body. Enzymes are proteins that act as biological catalysts, driving nearly every process in human physiology. They speed up chemical reactions without being consumed in the process. Enzymes lower activation energy to accelerate biochemical reactions, from breaking down sugars in the gut to neutralizing toxins in the liver. Enzymes are crucial for digestion, breaking down food into energy and nutrients across the stomach, intestines, and with the help of the pancreas. Even saliva contains digestive enzymes that begin the process of digestion before food reaches the stomach.
Each enzyme has a characteristic enzyme structure composed of chains of amino acids folded into precise three-dimensional shapes. This structure determines how enzymes work: a specific substance (the substrate) binds to the enzyme's active site, and the resulting enzyme reactions convert that substrate into products. Think of it like a lock and key at the cellular level.
Recombinant enzymes are engineered using recombinant DNA technology, meaning that the genes encoding a desired enzyme are inserted into microorganisms; bacteria such as E. coli and yeast are commonly used production hosts, where the enzyme is synthesized by those host cells at industrial scale. This approach, developed and refined since the 1980s, enables high purity and batch-to-batch consistency that older animal-derived preparations simply cannot match. Enzyme production can be enhanced by gene regulation mechanisms, allowing manufacturers to control expression levels and optimize yields.
In dermatology and aesthetics, the distinction matters enormously. Recombinant collagenase, hyaluronidase, and lipase are engineered to closely mimic human or therapeutically active enzymes while eliminating the impurities and immunogenic risks of bovine or ovine hyaluronidase preparations. For example, recombinant human hyaluronidase (rHuPH20) achieves a specific activity roughly 140–200 times higher than many animal-derived forms, with over 90% purity. That level of controlled enzyme levels is critical for injectable products used in skin and scar treatment, where predictable activity and reduced risk of allergic reactions determine clinical outcomes.
Pb-ee serum's recombinant enzymes are produced under GMP conditions in Europe (Albacete, Spain) and are designed specifically for aesthetic and regenerative indications. This sets them apart from older enzyme preparations that were never intended for intradermal or subcutaneous use.
Why Use Recombinant Enzymes for Scar Treatment?
Current established scar treatments include silicone, corticosteroid injections, and laser therapy. Each has well-documented limitations:
Surgical excision: High recurrence rates, especially for keloids (up to 50–80%). Creates a new wound and a new scar.
Corticosteroid injections: Repeated sessions cause skin atrophy, pigmentary changes, and telangiectasia. Recurrence remains common.
Laser therapy: Effective for color and some texture, but risks thermal injury and pigmentary alteration, particularly in darker skin phototypes.
Silicone sheets/gel: Helpful for prevention and mild scars, but limited impact on mature, dense fibrotic tissue.
Recombinant enzymes offer a different paradigm. They can selectively degrade excess ECM components in the scar, including collagen and glycosaminoglycans, while sparing surrounding healthy tissue when properly dosed. Recombinant enzymes aim to break down or remodel collagen-rich scar tissue through targeted biochemical reactions rather than thermal damage or surgical trauma.
Key advantages include:
Minimally invasive injections with potential for fewer sessions
Better texture and pliability improvement compared to steroids alone
Ability to combine with other modalities (microneedling, RF, lasers)
Treatments can be tailored to the specific substance composition of the lesion (e.g., collagen-dense versus edema-prone scars)
Early real-world data from aesthetic clinics in Spain, Italy, and Latin America using pb-ee serum recombinant enzymes in scar protocols since the mid-2010s have demonstrated encouraging results, with improvements identified from the first session in many patients.
Key Recombinant Enzymes Used in Scars: Collagenase, Hyaluronidase and Lipase
Three enzyme families play a crucial role in enzymatic scar management:
Enzyme | Target | Action in Scar Tissue |
Recombinant collagenase (PB220) | Type I & III collagen | Selectively digests abnormal collagen clusters in scars, softening and flattening raised tissue |
Recombinant hyaluronidase / lyase (PB72K, PB3000) | Hyaluronic acid, GAGs | Lyase cleaves hyaluronic acid in extracellular matrix to reduce tissue density, enabling diffusion |
Recombinant lipase (PB500) | Triglycerides in adipocytes | Lipase breaks down localized lipid deposits in fibrous tissue, reducing focal bulk and improving contour |
When combined in multi-enzyme formulations like pb-ee serum's medical line, these enzymes act synergistically. Collagenase dismantles the rigid collagen scaffold, lyase reduces the viscous ground substance, and lipase addresses fat pads that contribute to irregular scar contour. The combined effect is a softer, flatter, more pliable scar.
Products are typically lyophilized powders reconstituted immediately before injection to preserve activity and stability. Each vial is formulated with specific, calibrated unit activity to allow reproducible dosing across patients and sessions, giving healthcare providers confidence in consistent clinical outcomes.
Molecular Mechanisms: How Recombinant Enzymes Remodel Scar Tissue
At the molecular level, enzymes have specific active sites that bind substrates, and this lock-and-key specificity is what makes enzymatic scar treatment precise.
Collagenase action: Recombinant collagenase cleaves triple-helical collagen fibers within the ECM at defined cleavage sites. Class I and Class II collagenases target different regions of the collagen molecule, and collagenase clostridium histolyticum (approved for Dupuytren's contracture since 2011) demonstrates the clinical precedent for injecting collagenase into fibrotic tissue. In scars, this degradation breaks down the rigid scaffold that makes lesions raised and stiff.
Hyaluronidase/lyase action: Recombinant hyaluronidase degrades hyaluronic acid and other glycosaminoglycans, temporarily increasing tissue permeability. This enables better diffusion of co-administered enzymes and reduces the edema that contributes to scar volume.
Lipase action: Recombinant lipase hydrolyzes triglycerides in fat cells adjacent to thick scars, especially in post-surgical or post-traumatic areas. By converting stored triglycerides into glycerol and free fatty acids, lipase reduces focal bulges and improves contour.
Controlled enzymatic degradation triggers secondary biological responses. Reduced mechanical tension lowers the stimulus that perpetuates fibroblasts-to-myofibroblast transition. Improved microcirculation delivers oxygen and nutrients to previously ischemic tissue. Collagen reorganization occurs gradually over weeks, resulting in fibers more parallel to the skin surface. Recombinant enzymes can potentially enhance wound healing and tissue remodeling through these downstream effects, offering targeted matrix remodeling of abnormal scar tissue.
pb-ee serum Recombinant Enzymes: Technology and Product Concept
Pb-ee serum is a line of medical-grade recombinant enzyme products developed in Spain. Proteos Biotech specializes in producing recombinant enzymes for biomedicine and pioneered a recombinant DNA platform to obtain bacterial-origin enzymes structurally similar to human enzymes, manufactured under stringent GMP conditions.
Key technical features:
Enzymes are purified, then lyophilized for storage and standardized so clinicians can rely on consistent activity per vial across lots and countries. Enzymes can be lyophilized for storage without degradation, maintaining potency until reconstitution.
Storage at controlled room temperature (approximately 25°C ± 5°C) in dry, light-protected packaging. Use immediately after reconstitution to guarantee maximum potency.
The enzyme portfolio includes at least five recombinant enzymes: Keratinase PB333, Collagenases G/H PB220, Lipase PB500, Lyase PB72K, and Hyaluronidase PB3000.
Carriers include high molecular weight hyaluronic acid in the HA Low/Medium/High product lines. The HA carrier serves a dual function: it acts as a delivery vehicle and as an active ECM modulator, since high molecular weight HA can dampen TGF-β signaling.
Specific pb-ee serum formulations are CE-marked or registered as medical devices or medicinal products depending on the market. Prescribers must respect local regulatory labeling in each country where the products are available.
Indications: Types of Scars Suitable for Recombinant Enzyme Therapy
Injectable recombinant enzymes have been used across a range of scar types:
Hypertrophic surgical scars
Keloids (earlobe, chest, shoulders)
Post-acne fibrotic and atrophic scars
Traumatic scars (cuts, burns, grafted areas)
Tethered post-lipo or C-section scars
Good candidates typically present with mature but still active scars (usually 3–24 months after injury), palpable thickening, stiffness, and limited response to topical care. Patients should be willing to attend multiple sessions.
Contraindications include:
Active local infection
Unstable systemic disease (e.g., uncontrolled diabetes or coagulopathy)
Pregnancy or breastfeeding
Known allergy to formulation components
Very fresh open wounds
Effect on Fat Cells and Scar Volume
Some thick and retracted scars, particularly after surgery or trauma, sit on top of irregular or hypertrophic subcutaneous fat pads. This creates an uneven contour that goes beyond what collagen remodeling alone can address.
Inclusion of recombinant lipase in pb-ee serum formulations allows selective action on local fat cells, gently reducing their volume through triglyceride hydrolysis. A retrospective cohort of 343 patients treated in Caracas from 2018–2023 with tri-enzyme combinations demonstrated acceptable safety and efficacy for contouring and fibrosis remodeling.
The aesthetic benefit is tangible: smoother transition between scar and surrounding tissue, less bulging at scar edges, and more harmonious contour of the treated area. However, careful assessment is needed to avoid excessive volume loss. Treatment should be conservative, especially in areas where underlying fat provides important structural support (face, hands).
Optimizing Outcomes: Combining Recombinant Enzymes With Other Modalities
Recombinant enzymes do not exist in a therapeutic vacuum. Combination strategies include:
Enzymes + fractional lasers (CO₂ or Er:YAG): Enzymes soften and "open" the scar matrix first, then laser stimulates neocollagenesis and pigmentation normalization in subsequent sessions.
Enzymes + microneedling RF: Mechanical disruption combined with enzyme-driven ECM degradation has shown synergistic results in acne scar studies.
Enzymes + corticosteroid injections: For highly inflammatory keloids, a staged approach can address both the inflammatory and structural components.
Safety Profile, Adverse Effects and Contraindications
Recombinant enzymes typically carry a lower risk of side effects than traditional treatments, largely because they act locally and are rapidly inactivated by endogenous inhibitors.
Common transient effects reported in pb-ee serum studies:
Redness and edema (75–91% of patients in the HIGH pilot)
Mild to moderate pain at injection site
Bruising
Temporary induration
Almost all resolved within approximately 48 hours. No serious adverse events were reported, and no patients withdrew from treatment due to adverse reactions.
Uncommon risks:
Local over-correction or depressions if dosage is excessive
Pigmentary changes in darker phototypes
Allergic reactions to excipients (rare with recombinant proteins; more common with animal-derived forms)
Contraindications:
Pregnancy and breastfeeding
Severe coagulopathy
Active dermatologic infections
History of anaphylaxis to similar products
Injection into vascular structures (risk of ischemia)
Frequently Asked Questions About Recombinant Enzymes for Scars
How many sessions will I need? Most protocols involve 3–6 sessions spaced 2–4 weeks apart. The exact number depends on scar type, size, and severity. Improvement is typically gradual and cumulative.
Does it hurt? Lidocaine can be added to the reconstituted solution. Most patients report mild to moderate discomfort during injection, comparable to other intralesional treatments.
How long do results last? Clinical data suggests sustained improvement over months following a completed treatment course, though long-term follow-up data (beyond 12 months) is still limited. Recurrence rates for keloids specifically need more study.
Is it safe on dark skin? Early clinical series include patients of various skin phototypes. The risk of pigmentary changes is lower than with aggressive laser therapy, but conservative dosing is advisable in Fitzpatrick types IV–VI.
Can I treat acne scars with this? Yes. A recent study of 29 patients showed significant improvement in atrophic acne scars when recombinant enzymes were combined with microneedling over four sessions.
What about downtime? Expect mild swelling and tenderness for 24–72 hours, usually compatible with daily activities. Cold compresses help. Avoid intense exercise immediately after treatment.
Can I combine this with fillers or toxins? Yes, but spacing is important. Wait at least 2–4 weeks between enzyme injections and HA filler placement. Hyaluronidase in the enzyme cocktail could theoretically degrade freshly injected HA filler if administered too soon. The enzymes do not "travel" systemically or break down collagen and fat cells throughout the body; their action is local and transient.
Book an appointment with MODE Medical Clinic for Recombinant Enzymes treatment using Pb-ee Serum
